No single cause for cable car's litany of faults
The latest suspension of Lantau's cable car service on Wednesday came after a fourth technical fault in two months, but according to the operator the faults were all in different parts of the system.
After hundreds were trapped in cable car gondolas for around 90 minutes due to a fault, preliminary checks have shown a 42cm bearing on the haul rope pulley wheel at the Airport Island Angle Station to be slightly worn.
'We found no safety problem with the system. It is the reliability of service that is in question,' said Frank Chan Fan, director of electrical and mechanical services, adding that the system's six other identical bearings would be checked during a 10-day suspension.
He said the cold weather was unlikely to have caused the fault, since the cable car should be capable of withstanding Hong Kong's humidity and temperatures. Government-appointed experts reviewing the cable car's design after one fell to the ground in 2007 found it complied with international standards.
Professor Lo Kwok-keung, of Polytechnic University's department of mechanical engineering, said damage to the bearing was so minor it might not have been noticed during regular maintenance checks.
He said the part needed to be well lubricated, but if that had been done then the bearing might have been old and and ready for replacement. Or it might not have been of sufficient quality in the first place.
Metal parts could get worn out because of heavy loads or high windspeeds over long periods, while cold weather caused metal to contract and could lead to damage, Lo said.
Ngong Ping 360 managing director Wilson Shao said the incident was not related to a surge in passengers during Lunar New Year.
The cable car at Ocean Park has had fewer glitches over the years, but Lo said it was a different system, with a shorter route and half the parts of the Lantau one.
Professor Soh Ai-kah from the University of Hong Kong's mechanical engineering department said the city's climate should not be a problem for cable cars as the temperature range was small.
The twice-delayed Ngong Ping 360 cable car finally opens after system glitches put back its launch date by three months.
About 500 people are stranded on the ride when it stops for 43 minutes because the distance between cabins is too small.
An empty car falls 50 metres off the ropeway onto a hillside during a test run, prompting closure of the system for six months.
It is announced that the MTR Corporation will take over management of the cable car from Australian company Skyrail.
200 are stranded for 50 minutes when a faulty conveyor belt halts operations. Engineers insist the incident posed no danger.
A safety mechanism indicates two gondolas are too close, triggering a shutdown of the ride that leaves 200 stranded for 90 minutes.
About 250 passengers are trapped in mid-air for an hour when a faulty sensor halts the ride in the seventh disruption of the year.
Three stoppages occur in the month due to technical glitches - the longest leaves passengers hanging for 15 minutes.